Engine starter



J. E. ANToNlDls ETAL 2,944,428

ENGINE summa Filed oct. 11, 1957 July l2, 1960 vENToRs JoH/v E.ANTON/Dls r i. BY E BERT/IULM 211...

ATTORNEY United l SeteSPafmf' ,2,944,428 ENGINE *STARTER John E.Anmnidis and Robert 1A. zum, Anderson, and., Y

This invention relates to engine stalztersand .morepar- .tieula'rly ltoasta-rter drive ofthe inertia typefwherein `the pinion -is automaticallypropelled .into and-.from Aer'igageymentV with :the ,gear of vthe engineto be :.stfarted'.,

.It is an Aobject of the present invention'tofarrangethe' parts of astarter drive :on a threaded starting..motor .Shaft fso .the engine .tobe cranked may beftc'ranked fin either direction of rotation.

Another .object of the present invention is to..arrange the resilientmembers of aninertia .star-'ter' drive `so .a yielding ...connection isformed y,when-.the ,pinionismoved by thestarter motor and ya`nonyielding. yconnection Vis formed when the pinion is 4rotated-by theengine. This will .prevent rebounding .of Vthe pinion Egear into-engagementwith the engine gear after the engine .becomesselfoperative.

A ,A ,ftirther-objectof the present invention is to provide Aan inertiaLdrive with a torsion return. ,spring anda resilient .connection betweenv.the piniongear. fand. its.. drive `which will .permit .a limitedrotation betweenthe. ,pinion .gear and its drive when the pinion vismoved -by thestart- Ling motor and a non yielding connection. is formedwhen the vpinion is rotated bythe engine.- This aid. the ',pin'ion indemeshing from `the Vengine, gear andl will :prevent the pinion from.reboundinginto the engine ,gear after the engine becomes.self-operative..

Another object of the :present `inventionis :to v .r'nro'yide thestarting motor shaft with a .thread portion and- ,a smooth 'surfaceportion and .to support .a sleeve which axially moves on the threadportion, fon the 'smooth .surface portion With a nylon lbearing so thepinion which rides upon the sleeve will be supported when itv isjinmes'h with a gear ofthe engine to be started.

Another object of the present invention is to provide a shoulder'between a :reduced portion of ythe shaft and the remainder of Atheshaft which sholder'vvill act as fa stop to limit the `movement of asleeve which is V.threadedly connected to the reduced lportion of theshaft.

Patented July V1a, 1960 Y Figure 3 is'a View taken alonggli'ne iin'y:Figi-Ifo" 1.

"Figure` 4is`fa cross-sectional View 'ofi-ia `single vstai-ter drive*sliow'inga inodiiication 'of the drive-lin* V'Figure l'.

In I'the embodiment shown 'fin' Figures -l `and '2 'ofthe drawings, theshaft Z0 is adapted to be rotatedinf-cith'er direction lby aconyentionalttype starting motor, not shown. The shaftil `has afrednce'ddiameter portionJ 22 whichist separated :from `the main portion Q4 -ofvthe 'shaft 'by the shoulderj-Z. 'The reduced portion-of theShaft isprovided-with-threaded portionsY 2-8 -and '30 wliichfiare separated eaeh'other *byJ 4a smooth `surface' portion 82., :The threaded: -portions'28 and"3'0"3in the'enibodi- Irrentts'hown'iaree preferably formed-iinthe materia-loffthe jshaft '2ll This "arrangenrcn't will; provide acertain econ- 'onlyin-manuff-actre 'andf will Areduce the'over-alls'izeof f lthe remaining parts o'f the` starting, drive. AThe.threaded portions 'andf'lt Yare located opposite' sides 'of .avgeen-3124 which'is' connected to the engine to be startedlwhich",iis-not shown. lIn conventional practice, ythe` gear "34 wouldi-be connected tofthe' "ywheel 'and designated as a-'ring gear. .Theshaft '2:0 mayY also. begroov'edA as at and 38; lto :receive 'C-shaped`metal ringsj4ll` and' 42. The, ring 40 will `bepresse'd against theshoulder L26 and will preven tfda'niage thereto whenv the shoulder 'actsasa A stop; fiihering'42'isofa-hardened metal type andwill grooves whichreceive the C-shapedv rsnap rings 44 .and

.46j arranged to position one of :the ends. 'of the 'torsion springs.and; 49` respectively as shown. The function of'thesesprings `willbecome "hereinafter apparent.

.It to beunderstood that 'like numerals and7 :functions A further objectof the present inventionlis .toprovide i preferred embodiments ofthelpresent linvention are clear- 1y shown.

Inthe drawings: Y Figure 'l is a cross-sectional view vo'i' a pair fstarter `drives according to the present inventionwhic'h are arranged onopposite sides` of a gear'that isconn'ected to the engine-to be started.

Figure .2.` is a view of the drive fparts in Figurefl wherein one of thedrives is in lmeshing engagement with i `the engine gear.

dfthepartsto whichthe numbered parts relate willapply tothe 'parts of.the drive 52.. The drive 5l) includes the coupling 5'4, thepinion gear.56, the shell 58, .theresilient kmembers 6D and the snap ringf64 whichis received in `the internal groove ddngthe shell 58 tohold the'parts oflthe -drive'assembled y l The coupling 54' formed as shown has acentralhub 68` that is internally threaded to threadedly engage thethreaded .portion 2'8. The outwardly extending flange "70 on huh isprovided wi-thy av slot 72 to receive. fthe other vendaof the torsionspring 48 which has its convolutions surrounding 'the shaft `2t) whenthe driveY 50i-is 'inthe normal or at rest position. Extending .fromtheLange V`toward the pinion gear 5'6 are lugs. 74. The drive v.50

in vFigure lhas .four spaced lugs 74. These lugs are designatedas lugs,74A and' 74B and extend substantially radial- .ly from thei'hub 68 andare spaced as shown in Figure-3. The lugs 74A and 74B in 'the embodimentshownare providedby the extending arms of a pair .of U-shaped parts 76which have their central portions secured as 'by welding 'to the ange70. I

The .shell 58 is Vgenerally cup-shaped to have a vbottom wall 178, a.central opening 80' inthe bottom wall 478 and `the internal groove66wh'ich lis formed onthe sidewall 82; opposite sides thereof andadjacent .the bottom wall 78 is struck in to provide apair of'inwardlyextending lugs 84 which `extend substantially radially inwardly` as inFigure/3. When the partsof thedriye 50 are'ass'enrb'led, `the "lugs 84each 'will vhave one surfacer in engagement with one of thelugs 74A.Thus, 'one--snrface-oflngs 84"willbe in metal tometalconta'ct with thelng's'ifdl.

vPositioned between the' other surface of flugs 84A andthe fflrgs74Ba1'ethe resilientfmeinbersfll. f'

The material of the side Wall 82`jon diametrically.

central bore 86 sized to slide on the sleeve bearing 87 which ispositioned on smooth surface portion 32 of shaft 2t) and which is formedof nylon material or any otherrsuitable bearing material. This bearingmay be molded in place on the shaft or may be fitted thereto by anyother well known mechanical expedients. The teeth of the pinionareformed with the conventional chamfers to aid in the meshing anddemeshing with the ring gear 34.

The resilient members 60 are shaped as shown in Figs. 2 and 3. Thesemembers 60 are formed of rubber-like or elastomeric materials. Theparticular materials from which members 6) may be formed are Well knownand may consist of natural or synthetic rubber or other suitableplastics or combinations thereof which are compounded and cured toprovide the proper degree of resiliency. The members 60 are arcuate inshape and have `flat end walls arranged to engage the lugs 84 and 74B.

The inner surface 88 is curved to engage a portion of the cylindricalouter surface of hub 68. The outer surface 90 is also curved and ismaintained normally spaced from the complementary cylindrical surfaceprovided by the inner surface of side wall 82. The spacing between l Ythe outer surface 9@ and the inner surface of Wall 82 is maintained bythe lugs or bulbous portions 92 which extend outwardly from the surface90. The parallel end walls 94 have the spaced extending ribs 96 thereon.The ribs 96 are maintained constantly in engagement with the flange 70and the bottom wall '78 as in Figure l and are deformable to permit aslight axial movement between the hub 68 and shell 58.

When the shaft 28 is rotated in the direction of arrow 98 in Figure 3,the drive 50, because of its inertia will not rotate, but will moveaxially on the threaded portion Z8 to the right to the position shown inFigure 2. When the pinionis completely moved to the right, it will be inmesh with the ring gear 34 and the convolutions of the spring 48 will betightened about shaft Ztl. The

shock which accompanies the sudden stops of thepinion gear as it ismoved into the full mesh position is absorbed by the resilient members60 of drive 52. After the pinion 56 is in mesh with the ring gear 34,the continued rotation of the shaft 2&9 will rotate the hub 68. Therotation of the hub 68 will be transmitted through lugs 74B against theresilient members 60 to circumferentially compress the members '6hagainst lugs 84. When the resilient members are thus circumferentiallycompressed, the surface 96 will move radially outwardly to at leastpartly fill the space between the surface 90 and the inner cylindricalsurface of the side walls 82. Thus, a resilient connection is formedbetween the lugs 74B and 84 when the pinion gear 56 is driving the ringgear 34. 1n event tooth end abutment occurs between the pinion gear 56and the ring gear 34 when the pinion gear 56 is being moved forward intomeshing position with the ring gear 34, the resilient members 68 will beslightly axially and circumferentially compressed before the pinion gear56 rotationally responds -to the rotation of shaft 2t). This compressionof the resilient members 651 will aid the pinion in moving from itstooth end abutting position into full meshing position.

After the axial movement to the right of pinion gear 56 stops, thepinion will respond to the rotation of shaft 20 and rotate gear 34. Whenthe engine becomes selfoperative, ring gear 34 accelerates and will tendto have a greater rotational speed than pinion gear 56 and shaft 20.This relative rotation will cause the drive 5t) to be rotated on threadportion 28 and move to the left from the position in Figure 2 so thepinion gear 55 will move from its meshing engagement with the ring gear.The spring 48, which was previously stressed when the pinion y gear 56moved into the meshing position will aid the movement of the pinion gear56 to the left. During this period, a relatively nonresilient drivingconnection will be formed between the pinion gear 56 and the hubp68.

4 This nonresilient connection is the result of the metal to metalcontact between lugs 74A and lugs 84 and will impart a positivenonresilient rotative impulse to the hub to eliminate the back lash orkickback which occurs when the pinion is connected to the hub by aconnectlon that is resilient in both directions of rotation` We havedetermined that a nonresilient connection, as described, between thepinion gear 56 and hub 68, will eliminate the rebounding of the piniongear into the ring gear after the engine becomes self-operative.

4 The threads of both threaded portions 28 and 38 are left-handed.Therefore, when the shaft 28 rotates clockwise as viewed in Figure 3,the drive 5@ will advance from left to right and drive 52 will bepressed against the ring 42. In this connection, itis noted that thetorsion springs 4S which normally loosely surround the shaft 20 willnormally maintain the drives against the rings 40 and 42 when the shaft20 is not rotating. When theshaft is rotated to move one of the drivestoward the gearv34, the spring associated with the moving drive willbecome 'extended and its ccnvolutions decreased in diameter.

The springs will thus aid the pinion gear drive in demeshing from thering gear after the engine becomes self-operative. When the shaft Ztl isrotated in a clockwise direction, the drive 52 will advance from rightto left as shown in Figure l. The parts of this drive 52 will functionin the same manner as the corresponding parts described for drive 50. Itis clearly apparent that the above arrangement will cause the engine tobe cranked in either direction of rotation depending on the direction ofrotation of shaft 20.

In the embodiment shown in Figures 4 and 5 of the drawings, the shaft12o is arranged to be driven in one direction of rotation only,indicated by the arrow in Figure 5, by a starting motor, not shown. Thedrive 122 'includes a sleeve 124 which is internally threaded to engagethe threaded portion 126 of the shaft 120. A flanged member 128 securedto sleeve l124 has lugs 130 which radially extend from the oppositesid'es of sleeve 124 and extend longitudinally along the outer surfaceof the sleeve toward the pinion gear 132 in a plane parallel Vwith theaxis of the shaft 12h. VThe purpose of these is, one surface of each ofthe lugs will be in engagement vwith a resilient member 138 while theother surface Will be metal to metal contact with an adjacent metal lug.Secured to the outer surface of coupling 134 is a shell 140. This shell140 will have its free end riding upon the flange 128 and willcompletely enclose the lugs 136 .and and will provide enclosed areas orchambers 142 between the shell 140, the outer surface of the sleeve 124and the adjacent surfaces of the lugs 136 and 130.

Positioned' within each of the chambers 142 are resilient members y138.Each of these members 138 is formed of a suitable elastomeric compoundsuch as the well-known natural or synthetic rubbers, a suitable organic'plastic or mixtures thereof which are compounded to provide the properresilient `characteristics thereto. The

-members 138 are sized to not completely ll the spaces 142. The members138 have provided lugs or bulbous yportions 144 thereon. These lugs 144are arranged to 70.

engage the outer shell V to provide an open space 146 between the outersurface of members 138 and the inner surface of the shell 140. Thisspace 146 will permit the rubber material forming members 138 to moveradially .outwardly when abutment 136 is rotated relative to abutment130.` It is well known that rubber isvvirtually uncompressible. Thisspace will permit the rubber to provide the yielding restraint to opposethe movement between the abutments 136 and 130. The members' 138 arealso provided with ribs or ridges 147 which have their apexes inconstant engagement with the members 128 and 134. These apexes of ribs147 are arranged to provide an increased resistance to movementproportional to the distance moved when the coupling 134 and flange 128are moved toward each other.

The shaft 120 is also provided 'with a stop, portion 148 which isengaged by sleeve 124. The drive parts are held assembled on sleeve 124by the snap lring 149 which isV arranged to permit the pinion gear 132tovmove axially on sleeve 124 toward flange 128. A conventional fixedstop means 150 on the free end of shaft 120 will limit the axialmovement of they drive to the right. In this embodiment the torsionalspring 48 as used in the embodiment shown in Figure l is replaced by acompression spring 152.

The parts of the starter drive will have a similar operation duringmeshing and' demeshing operation with the ring gear 154 as described inthe embodiment shown in Figure 1.

While the embodiments of the present invention as herein disclosedconstitute preferred forms, it is to be understood that other Vformsmight be adopted.

What is claimed is as follows:

1. In an inertia type starting motor drive, comprising: a nut having athreaded engagement with a threaded portion on a starting motor shaft,outwardly extending lugs Von the nut, a pinion gear slid'able androtatable over a smooth portion of the shaft, a shell connected tothepinion, and inwardly turned lugs integral with and extending from theshell interposed between the lugs on the nut and in metal to metalcontact therewith, said lugs forming a direct drive between said nut andpinion.

2. In an inertia type starter drive, the combination comprising: a nuthaving a threaded engagement with a threaded portion on a starting motorshaft, outwardly extending lugs on the nut, a pinion gear slidable androtatable over a smooth portion of ,the shaft, a shell connected to thepinion, an integral inwardly turned lug on the shell having a surface incontact with a lug on the nut and a resilient means disposed between thelugs on the nut and on the shell urging the lug on the shell intosurface contact with the lug on the nut, said resilient means forming aresilient drive in one direction of movement of said pinion and saidlugs forming a direct drive in an opposite direction of movement of saidpinion.

3. In an engne starting apparatus, the combination comprising: arotatable shaft, a threaded portion on the shaft, a sleeve having anouter smooth surface threaded on the threaded portion and axiallymovable on said shaft when said shaft is rotated, spaced lugs on thesleeve, a pinion gear freely movable axially and rotatively on saidsleeve, spaced lugs connected to said pinion interposed between and incontact with the lugs on the sleeve, a shell connected to the pinion andenclosing said lugs to provide a confined space between adjacentinterposed lugs on the sleeve and pinion, and a resilient means in thespace between the adjacent lugs to provide a resilient connectionbetween the pinion and sleeve in one direction of rotation only. y

4. In an engine starting apparatus, the combination comprising: arotatable shaft, a threaded portion on the shaft, a sleevehaving anouter smooth surface threaded on the threaded portion and axiallymovable on the shaft when the shaft is rotated, a pinion gear'freelymovable axially and rotatively on the sleeve, a flange on the sleeve,spaced abutments extending from. the flange longitudinally along theouter surface of the sleeve toward said pinion, spaced abutmentsconnected to the pinion extending toward the flange and interposedbetween the abutments on the ange, a shell connected with the pinion andenclosing said abutments to provide a plurality of confined' spacesbetween the adjacent interposed abutments on the pinion and flange, anda resilient means yieldably resisting longitudinal movement of thepinionon said sleeve and sized to permit a limited free rotary movement of thepinion on `the sleeve in one direction of rotation only.

5. In a starting apparatus for an engine, the combination comprising: arotatable shaft, a nut threadedly connected with said shaft and adaptedto be moved axially on said shaft a predetermined distance in responset0 relative rotation between the sleeve and shaft, a pinion gearfreelymovable on said shaft and movable into mesh with-a gear connected withthe engine to be started,

a means resiliently connecting the pinion and nut and a torsion springconnected between the shaft and nut for aiding the movement of thepinion from its meshing engagement with the gear after the enginebecomes selfoperative.

6. In a starting apparatus for an engine, the combination comprising: arotatable shaft, a nut threadedly connected with the shaft and adaptedto move axially on said shaft in response Vto relative rotation betweenthe' v shaft and nut, a pinion freely movable on the shaft and movableinto meshing engagement with a gear connected with the engine to becranked, a torsion spring surrounding said shaft and connected with thenut and shaft for yieldably opposing movement of the pinion on the shaftand means connecting the pinion and nut.

7. In a starting apparatus for an engine, the combination comprising: arotatable shaft, a reduced portion on said shaft having a shoulderseparating the lreduced portion of the shaft from the remainder of theshaft, a washer engaging said shoulder, a threaded portion on saidreduced portion adjacent the shoulder, a smooth surface on said reducedportion, a nut having internal threads engageable with the threadedportion and the smooth surface portion, said nut being axially movableon the reduced portion of the shaft in response to relative rotationbetween the shaft and nut.

8. The combination as set forth in claim 4 wherein the resilient meansconsists of rubber-like members having oppositely extending ridges inengagement with the flange and pinion which are adapted to compress andyieldably maintain pinion and sleeve axially in position.

9. In a starting apparatus for an engine, the combination comprising: arotatable shaft, a reduced portion on said shaft forming a shoulderseparating the reduced portion of the shaft from the remainder of theshaft, a threaded portion on said reduced portion located adjacent theshoulder, a nut having internal threads engageable with the threadedportion, a pinion rotatable and slidable on said shaft and driven bysaid nut, resilient means disposed between said pinion and nut fortaking up axial shock therebetween, and a torsion spring having one endthereof connected to and engaging said shaft and having an opposite end`connected with said nut for urging said nut toward said shoulder.

' References Cited inthe le of this patent UNITED STATES PATENTS1,625,793 Chilton Apr. 26, 1927 1,807,772 Chryst .Tune 2, 1931 1,844,543Codrington Feb. 9, 1932 2,237,816 Getzet `al Apr. 8, 1941 2,847,985Strang Aug. 19, 1958

